Not entirely accurate, that will help clean surface dust but if you have multiple systems sitting for long periods of time it won't prevent dust from entering the system. Also any type of sunlight exposed to the systems over long periods will result in weathering to the plastic which can and will result in fading, warping and eventually cracks.

These are pretty amazing and look like the systems they keep dust free so it's not just covered up and unseen. They also account for cables so there's spaces on the back so they can remain plugged in.
https://www.etsy.com/shop/PrinterBoy?ref=ks_wide